It's a questionable source with dead links that doesnt link the ATF statistics. This part doesn't seem totally on the up and up though...
ATF officials say that only about 8% of the nation's 124,000 retail gun dealers sell the majority of handguns that are used in crimes. They conclude that these licensed retailers are part of a block of rogue entrepreneurs tempted by the big profits of gun trafficking. Cracking down on these dealers continues to be a priority for the ATF. What's needed, according to Wachtel, is better monitoring of the activities of legally licensed gun dealers.
The above is illegal and there are laws in place to stop this activity. For the ATF to claim to know this and still can't stop it indicates a level of incompetence in my eyes...
More laws the ATF doesnt enforce doesnt help the situation.